This disclosure is generally directed to photoreceptors, photoconductors, and the like. More specifically, the present disclosure is directed to multilayered drum, or flexible, belt imaging members, or devices comprised of a first layer, a supporting medium like a substrate, a photogenerating layer, and a charge transport layer (CTL), including a plurality of CTLs, such as a first CTL and a second CTL, an optional adhesive layer, an optional hole blocking or undercoat layer, and an optional overcoat layer. More specifically, the photoconductors disclosed contain a CTL comprised of a polysiloxane-b-polyetherimide block copolymer.
The CTL of the present disclosure possesses a desirable low surface energy, thus the wear resistance of this layer is excellent and is comparable to a CTL containing a polytetrafluoroethylene (PTFE). Moreover, the CTL of the present disclosure contains an environmentally non-hazardous polymer as compared, for example, to PTFE; the coating solution containing the polysiloxane/polyetherimide copolymer is stable for extended time periods; minimal agglomeration of the CTL layer components result thereby increasing the slipperiness of this layer as compared to a CTL with micron-sized particles of PTFE; the use of molecularly dispersed (soluble) or micro phase separated (nano-sized domains) additives of a polysiloxane/polyetherimide copolymer, such as a polysiloxane-b-polyetherimide copolymer, that substantially avoid the escape of the polymer particles when the CTL is worn down that adversely impact the systems in which the CTL layer is present; and other advantages as illustrated herein for photoconductors with charge transport layers comprising a polysiloxane/polyetherimide copolymer.
The CTL layer, which can be solution coated, for example, on the photogenerating layer may comprise a number of suitable polysiloxane-b-polyetherimide materials such as those components that substantially reduce surface contact friction and prevent or minimize wear/scratch problems for the photoreceptor device. In embodiments, the mechanically robust CTL layer of the present disclosure usually will not substantially reduce the layer's thickness over extended time periods to thereby adversely affect its hole transport characteristics causing print defects which prevent the imaging process from continuously allowing a satisfactory quality copy or printout quality; and moreover, CTL wear also produces dirt and debris resulting in dusty machine operation condition.
The CTL layers illustrated herein, in embodiments, have excellent wear resistance, extended lifetimes, and permit the elimination or minimization of photoconductive imaging member belt CTL scratches.
Also included within the scope of the present disclosure are methods of imaging and printing with the photoresponsive or photoconductor devices illustrated herein. These methods generally involve the formation of an electrostatic latent image on the imaging member, followed by developing the image with a toner composition comprised, for example, of thermoplastic resin, colorant, such as pigment, charge additive, and surface additive, reference U.S. Pat. Nos. 4,560,635; 4,298,697 and 4,338,390, the disclosures of which are totally incorporated herein by reference, subsequently transferring the toner image to a suitable image receiving substrate, and permanently affixing the image thereto. In those environments wherein the device is to be used in a printing mode, the imaging method involves the same operation with the exception that exposure can be accomplished with a laser device or image bar. More specifically, the flexible photoconductor belts disclosed herein can be selected for the Xerox Corporation iGEN® machines that generate with some versions over 100 copies per minute. Processes of imaging, especially xerographic imaging and printing, including digital and/or color printing, are thus encompassed by the present disclosure. The imaging members are in embodiments sensitive in the wavelength region of, for example, from about 400 to about 900 nanometers, and in particular from about 650 to about 850 nanometers, thus diode lasers can be selected as the light source. Moreover, the imaging members of this disclosure are useful in color xerographic applications, particularly high-speed color copying and printing processes.